Molecular identification of the entomopathogen Aspergillus candidus and its pathogenicity to the mealybug Phenacoccus solenopsis (Hemiptera : Pseudococcidae)‎ in Egyptian sugar beet fields

Abstract EN

reduction in photosynthetic processes.

Biological control is an essential approach to control.

The fungus Aspergillus candidus is one of the entomopathogens attacking this mealybug.

The current investigation was done at "Kafr Ascar" village, Kafr El-Sheikh Governorate, Egypt during 2016/2017 and 2017/2018 seasons.

Obtained results indicated that the natural mortality of P.

solenopsis adults due to the fungus A.

candidus infection in the field ranged between 2-19 individuals/ 50 plants from 25 October to 10 May, 2016/2017 season and the total number of dead insects recorded throughout the season was 71 individuals/ 300 plants.

According to statistical analysis, the results indicated that the temperature and humidity had a significant effect on the activity of the fungus and therefore on mortality rates.The entomopathogenic fungus was isolated and identified by GATC (Biotech Sequence Company, Germany), as A.

candidus strain HNMF075 (Ascomycetes: Eurotiaceae) for the first time in Egypt.

Suspension of this fungus was made, adjusted to 5X 105 spores/ ml water, for using in laboratory and field tests.

In a laboratory tests, the mortalities of adults were 55.00 and 95.00 two and four days after treatment, respectively.

The mean of mortality was 75.00 %.

Also, in a field tests, the reductions of adults were 53.00 and 67.42% two and four days after treatment, respectively, with 60.21% average reduction based on DNA sequences using rDNA, data showed that the Aspergillus isolate belonged to A.

candidus with a high similarity of 94%.

It is concluded that A.

candidus strain HNMF075 is an effective biological agent against P.

solenops is in sugar beet fields in Egypt.